Getting Started with Grasshopper

From TOI-Pedia

Starting Grasshopper

Expected Time: 20 min
Start Grasshopper using the command line

Grasshopper is an add-on or plugin for Rhino. It is part of the default Rhino 6+ installation. This is a link to the official Grasshopper website. This site offers a lot of tutorials, forums and links to other websites.

Starting Grashopper can be done by typing grasshopper in the Rhino command line. Grasshopper will open on top of Rhino. You can also click on the Grasshopper icon in the toolbar.


A Grasshopper script

Grasshopper is an add-on for Rhino which offers explicit history modeling. This term requires some explanation:

Rhino doesn't always keep track on how the model was constructed. Some other 3D modeling applications 'remember' for example from which set of curves a surface was created. When you change these curves, the surface will change accordingly as if it was newly created. This is called a history. Software such as Maya and 3DS Max implement the concept of history. It supports the design process by enabling you to go back to earlier steps of the modeling process and change them, thereby changing the end result. Rhino is limited in its support for history.

A box is moved to the right, but the original box is still visible: Explicit History

To address this, the concept of Explicit History was developed for Rhino. This formed the basis of what is now the Grasshopper plug-in. Explicit history is clearly visible in Grasshopper. As you may notice when you start building your scripts, the steps you take to get the final result are saved intermediately, and can be re-used for other goals.

The result of a Grasshopper script

Explicit History differs from the traditional modeling history in that you explicitly construct the History and thereby the object instead of being the result of a set of commands generating an object. This can be effective in the design process as it enables you to specify complex relationships between components.

Each Grasshopper definition consists of a network of components connected using connections and with sliders as input. Grasshopper uses the Rhino viewport to display the result of the definition.

It is recommended to now take a look at the Introduction Grasshopper Geometry and Grasshopper Interface.

List of important terminology


The Grasshopper Toipedia uses some specific terminology. Here is a brief explanation of the most important terms that are used throughout this article:

  • Component: a building-block that performs a specific action
  • Parameter: a special component that contains data (values) instead of performing an action
  • Number Slider: a utility that allows the user to choose numeric values using a slider
  • Panel: a utility that allows the user to define or display numeric values or text
  • Definition: a network of grasshopper components - your Grasshopper 'model'

TOI Course Material Levels Grasshopper

The tutorials on the Grasshopper Toipedia, can be divided into several categories:

INTRODUCTORY: Introducing basic concepts of Grasshopper, such as:

  • Terminology
  • Interface & Navigation
  • Simple Setup of Definitions

BEGINNER: Learning materials cover all basic concepts of Grasshopper without great depth, such as:

  • Basic Geometry (such as Points, Curves, Surface, Breps)
  • Transformations
  • Data Trees Explanation

INTERMEDIATE: Learning materials cover intermediate concepts of Grasshopper both in breadth and depth.

  • Complex Geometry (more complexity than Basic Geometry)
  • Parametric Relations (Attractor and Distance-based)
  • Data Trees Manipulation

ADVANCED: Learning materials cover advanced concepts of Grasshopper, including:

  • Complex Geometry (more complexity than at Intermediate Level)
  • Analysis
  • Parametric Relations (Performance-based)
  • Rationalization & Optimization
  • Data Trees Coupling

MASTER: Learning materials cover concepts of Grasshopper at the level of the Master-Thesis, including:

  • Complex Geometry (more complexity than at Advanced Level)
  • Simulation
  • Advanced Data Extraction
  • Computational Intelligence
  • Exchange of Data using other Softwares (such Revit, ModeFrontier, Finite Element Analysis & Light Simulation Analysis Software, etc.)

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